There are a number of agents currently available in the market for diabetes management, which belongs to various structural types. For example, thiazolidinediones, sulfonyl ureas, alpha-glucosidase inhibitors and biguanides are some of the drug types currently available in the market. According to the American Diabetes Association, diabetes mellitus is estimated to effect 6% of the world population and the recent studies indicate that the number of diabetic patients could rise to 300 million by 2025. Worldwide sales of antidiabetic drugs reached 10 billion US dollars in 2002. Oral antidiabetics accounted for 63% of these sales and glucophase (metformin) was the leading product. With rising number of people suffering from diabetes worldwide, the market for diabetes medications could exceed $20 billion by 2006. In the natural products arena, a handful of herbal medications were proven to be effective against this terrible menace. For example, Fenugreek (Trigonella foenumgraecum), Gymnema (Gymnema sylvestre), Jamun/Jambolan (Syzygium cumini), Bitter melon/Karela (Momordica charantia) and Banaba (Lagerstroemia speciosa) are some of the products known to show hypoglycemic activity. Natural antidiabetic treatments have gained popularity in the recent years because of their proven safety from long history of usage in traditional medicine and also present usage in herbal treatments. Banaba, Lagerstroemia speciosa L, has gotten the worldwide attention in the past few years as organic insulin. It is widely distributed in Philippines, as well as in Malaysia, South China and tropical Australia. Corosolic acid or colosolic acid (2α-hydroxyursolic acid, CAS No. 4547-24-4), a triterpenoid compound isolated from the banaba extract was found to be responsible for the antidiabetic activity. Banaba has long been recognized for the treatment of diabetes and also for maintenance of low blood pressure and improved kidney function in Philippines and other East Asian countries. Clinical studies confirmed the hypoglycemic effects of corosolic acid (Judy, W. V. et. al., J. Ethnopharmacol., 2003, 87(1), 115-7). Indian species of Lagerstroemia (Lagerstroemia parviflora, Lagerstroemia indica, Lagerstroemia speciosa, etc), which grows along east coast from Orissa to West Bengal, also produce corosolic acid. Matsuyama, U.S. Pat. No. 6,485,760 (2002) described the blood sugar lowering effect of Lagerstroemia extract.

Presently, there has been a tremendous surge in the demand for non-steroidal, plant based anti-inflammatory agents. 5-Lipoxygenase is the key enzyme for the biosynthesis of leukotrienes and 5(S)-HETE, the important mediators, for inflammatory, allergic and obstructive process, from arachidonic acid. 5-Lipoxygenase is the target enzyme for identifying inhibitors, which have the potential to cope with a variety of inflammations and hypersensitivity-based human diseases including asthma, arthritis, bowl diseases such as ulcerative colitis and circulatory disorders such as shock and ischaemia. Scientists around the world have invested major effort during the last ten years, in identifying 5-lipoxygenase inhibitors from plant sources. Gum resin of Boswellia species known as Indian frankincense has been used as an anti-inflammatory agent in traditional Ayurvedic Medicine in India. The source of anti-inflammatory actions has been attributed to boswellic acids (Safayhi, H., et al., Planta Medica, 1997, 63, 487-493 and J. Pharmacol. Exp. Ther., 1992, 261, 1143-46, both the journals published from USA), a group of triterpene acids isolated from the Boswellia resin (Padhy, R. S., et al., Indian J. Chem., 1978, 16B, 176-178). During our search for new anti-inflammatory agents, we have observed, to the best of our knowledge for the first time that corosolic acid is a potential inhibitor of 5-LOX. The inhibitory activity was found to be on par with 3-O-acetyl-11-keto-β-boswellic acid (AKBA).
The olenane and ursane triterpenoids also gained prominence recently for their antiproliferative actions. As 5-lipoxygenase (5-LOX) is the first enzyme in the metabolic pathway leading to the formation of leukotrienes and eicosanoids that are important in carcinogenesis process, inhibitors of 5-LOX may thus have profound influence on the growth and apoptosis of various cancer lines (Yong S. Park, et. al., Planta Medica, 2002, 68, 397-401). Boswellic acids, for example inhibited several leukemia cell lines in vitro and inhibited melanoma growth and induced apoptosis (Hostanska, K., et. al., Anticancer Res., 2002, 22(5), 2853-62). The acetyl boswellic acids were found to be unique class of dual inhibitors of human topoisomerages I and II α (Syrovets, T. et. al., Mol. Pharmacol., 2000, 58(1), 71-81). A number of oleanane and ursane tripenoids were found to be powerful inhibitors of nitric oxide production in macrophases, which can be correlated to their cancer chemoprevention activity (Honda, T. et. al., J. Med. Chem., 2000, 43, 1866-77). Corosolic acid, which has the gross structure very similar to AKBA and other ursane derivatives, may thus hold promise as an antitumor agent.